Add Sentinel AI to Machine Learning section

[MaxwellCalkin]

What is Sentinel AI?

Sentinel AI is a real-time safety guardrails library for LLM applications. It provides 8 production-ready scanners (prompt injection, PII detection, harmful content, hallucination, toxicity, blocked terms, tool-use validation, and structured output validation) with sub-millisecond latency (~0.05ms average).

Why Machine Learning?

Sentinel AI is designed to work alongside LLM frameworks already listed in this section — LangChain, LlamaIndex, Instructor, and pydantic-ai — providing the safety and content moderation layer that these frameworks lack. It scans LLM inputs and outputs in real time, making it an essential companion library for anyone building ML/LLM-powered applications.

Key highlights

• 8 safety scanners covering prompt injection, PII, toxicity, hallucination detection, and more
• Sub-millisecond latency (~0.05ms avg) — designed for real-time production use
• 530 benchmark cases with 100% accuracy (0 false positives, 0 false negatives)
• Zero heavy dependencies in core (only regex)
• MCP Safety Proxy for transparent safety on any MCP server
• Multilingual injection detection across 12 languages
• Apache 2.0 licensed
• Python-first (>95% Python codebase)
• Active development with recent commits

Category: Hidden Gem

Sentinel AI addresses the critical and growing need for LLM safety guardrails — a space where no equivalent Python library exists in this list. As LLM adoption accelerates, safety scanning is becoming essential infrastructure for production ML applications.

Repository: https://github.com/MaxwellCalkin/sentinel-ai

[JinyangWang27]

@MaxwellCalkin Thanks for you submission. However, this project does not meet our acceptance criteria:

Repository age: The repository was created 2 days ago. We require a minimum of 3 months (or 6 months for Hidden Gem submissions) to ensure project stability.

GitHub stars: 0 stars (minimum 100 required, or strong justification for Hidden Gem).

Please see our CONTRIBUTING.md for full requirements. You're welcome to resubmit once the project has matured and gained community traction.